The field of the present invention is anti-lock brake systems for motorcycles.
Anti-lock braking systems for the front wheel of a motorcycle have been developed which include a master cylinder which may be actuated by the operator, a front wheel brake operated by the master cylinder through a brake line therebetween and an anti-lock control unit interposed in the brake line between the master cylinder and the front wheel brake. The anti-lock control unit is adapted to sense the nearly-locked condition of a front wheel and shut off the hydraulic pressure to the brake itself. One such braking system is disclosed in Japanese Patent Laid-open Publication No. 120440/1981.
With the motorcycle provided with such an anti-lock braking system, the chassis may vibrate when the front wheel brake is applied. This vibration occurs in a vertical direction with the repeated operation of an anti-lock control unit which rapidly cycles the brake on and off under conditions of approaching wheel lock. The problem is aggregated with motorcycles having high centers of gravity and short wheel bases.
The reaction of the front fork responsive to the action of braking and of the anti-lock braking device is to begin to dive. As the dive commences, a short period of time exists where there is no increase of the front wheel load on the tire contact with the ground. Consequently, there is no increase in the resistance to locking of the brake during that short period. Consequently, a slight decrease in braking efficiency could theoretically be experienced.